/It may be a decent indicator, but what's the point? Are you all out of fresh exams? Unless you've finished all the the exams in the 60s 70s and 80s I would probably opt for a new exam over retaking an old one personally.
I am focusing on the "modern era" tests, 70-80s. I could be completely wrong, but some of the LR questions seem more subtle, and the RC I have trouble finishing whereas I did not struggle to finish RC on the 50-60s. Could just be me.